Introducing Data::Tumbler and Test::WriteVariants

For some time now Jens Rehsack (‎Sno‎), H.Merijn Brand (‎Tux‎) and I have been working on bootstrapping a large project to provide a common test suite for the DBI that can be reused by drivers to test their conformance to the DBI specification.

This post isn’t about that. This post is about two spin-off modules that might seem unrelated: Data::Tumbler and Test::WriteVariants, and the Perl QA Hackathon that saw them released.

Continue reading

NYTProf v5 – Flaming Precision

As soon as I saw a Flame Graph visualization I knew it would make a great addition to NYTProf. So I’m delighted that the new Devel::NYTProf version 5.00, just released, has a Flame Graph as the main feature of the index page.

nytprof-v5-flamegraph.png

In this post I’ll explain the Flame Graph visualization, the new ‘subroutine calls event stream’ that makes the Flame Graph possible, and other recent changes, including improved precision in the subroutine profiler. Continue reading

Introducing Devel::SizeMe – Visualizing Perl Memory Use

For a long time I’ve wanted to create a module that would shed light on how perl uses memory. This year I decided to do something about it.

My research and development didn’t yield much fruit in time for OSCON in July, where my talk ended up being about my research and plans. (I also tried to explain that RSS isn’t a useful measurement for this, and that malloc buffering means even total process size isn’t a very useful measurement.) I was invited to speak at YAPC::Asia in Tokyo in September and really wanted to have something worthwhile to demonstrate there.

I’m delighted to say that some frantic hacking (aka Conference Driven Development) yielded a working demo just in time and, after a little more polish, I’ve now uploaded Devel::SizeMe to CPAN.

In this post I want to introduce you to Devel::SizeMe, show some screenshots, a screencast of the talk and demo, and outline current issues and plans for future development. Continue reading

What’s actually installed in that perl library?

A key part of my plan for Upgrading from Perl 5.8 is the ability to take a perl library installed for one version of perl, and reinstall it for a different version of perl.

To do that you have to know exactly what distributions were installed in the original library. And not just which distributions, but which versions of those distributions.

I’ve a solution for that now. It turned out to be rather harder to solve than I’d thought… Continue reading

Upgrading from Perl 5.8

Imagine…

  1. You have a production system, with many different kinds of application services running on many servers, all using the perl 5.8.8 supplied by the system.
  2. You want to upgrade to use perl 5.14.1
  3. You don’t want to change the system perl.
  4. You’re using CPAN modules that are slightly out of date but you can’t upgrade them because newer versions have dependencies that require perl 5.10.
  5. The perl application codebase is large and has poor test coverage.
  6. You want developers to be able to easily test their code with different versions of perl.
  7. You don’t want a risky all-at-once “big bang” upgrade. Individual production installations should be able to use different perl versions, even if only for a few days, and to switch back and forth easily.
  8. You want to simplify future perl upgrades.

I imagine there are lots of people in similar situations.

In this post I want to explore how I’m tackling a similar problem, both for my own benefit and in the hope it’ll be useful to others. Continue reading

Looking for a Senior Developer job? TigerLead is Hiring again in West LA

The company I work for, TigerLead.com, has another job opening in West LA:

As a Senior Developer, you will be playing a central role in the design, development, and delivery of cutting-edge web applications for one of the most heavily-trafficked network of real estate sites on the web. You will work in a small, collaborative environment with other seasoned pros and with the direct support of the company’s owners and senior management. Your canvas and raw materials include rich data sets totaling several million property listings replenished daily by hundreds of external data feeds. This valuable data and our powerful end-user tools to access it are deployed across several thousand real estate search sites used by more than a million home-buyer leads and growing by 50K+ users each month. The 1M+ leads using our search tools are in turn tracked and cultivated by the several thousand real estate professionals using our management software. This is an outstanding opportunity to see your creations immediately embraced by a large community of users as you work within a creative and supportive environment that is both professional and non-bureaucratic at the same time, offering the positives of a start-up culture without the drama and instability.

If that sounds like interesting work to you then take a look at the full job posting.

TigerLead is a lovely company to work for and this is a great opportunity. Highly recommended.